While 50 percent of Americans don't consider the war to be a success, 39 percent of Americans do.

When respondents' answers were broken down by political group -- Democrat, independent and Republican -- Republicans were the only political group where more respondents considered the war a success (49 percent) than didn't (41 percent). Fifty-five percent of Democrats don't consider the war a success; 35 percent do. With independents, thirty-six percent called the war a success and 52 percent didn't.

CBS

The poll found that majorities of all three of those political groups thought the war has lasted longer than anticipated. As a whole, 69 percent of Americans said the war has lasted longer than they expected. Twenty-five percent said the war's length has been about as expected.

Most Americans want to see troop levels decrease in Afghanistan. This comes as President Obama's withdrawal plan is expected to pull 10,000 troops from the country by the end of the year and the 33,000 "surge" troops by summer 2012.

Sixty-two percent of Americans want lower troop levels, the poll found, compared with 24 percent that want troop levels kept the same and 7 percent that want them increased. The percentage of Americans calling for increased troop levels in the country has sharply decreased from the 34 percent who wanted that in January 2009, when Mr. Obama was sworn into office.

CBS

This poll was conducted by telephone from Sept. 28, 2011, to Oct. 2, 2011, among 1,012 adults nationwide. Phone numbers were dialed from samples of both standard land-line and cell phones. The error due to sampling for results based on the entire sample could be plus or minus 3 percentage points. The error for subgroups is higher. This poll release conforms to the Standards of Disclosure of the National Council on Public Polls.